Sam's Club CEO Brian Cornell has resigned the post, and parent Wal-Mart has named Rosalind Brewer as the 610-store warehouse chain's new chief executive. Brewer, who currently heads Wal-Mart stores in the Northeast, will be the first woman to lead one of the retailer's major business units.

Wal-Mart Stores said Monday it will close 10 underperforming Sam's Club warehouse stores across the country, cutting 1,500 jobs. In a letter to employees, the company said it would work with staffers to find positions elsewhere. Wal-Mart also said it expects to open up to 10 new Sam's locations, and remodel as many as 80 stores.

Big-box retail chains are treating their roofs as valuable real estate, installing solar panels capable of generating up to 40% of a store's power needs. Kohl's, Macy's and Safeway are among the chains jumping on the trend, though analysts say a congressional extension of clean-energy tax credits will be needed to maintain momentum. Wal-Mart, which has 17 stores and distribution centers testing solar panels, says a total build-out across the chain would create solar acreage roughly the size of Manhattan.

Big-box retail chains are treating their roofs as valuable real estate, installing solar panels capable of generating up to 40% of a store's power needs. Kohl's, Macy's and Safeway are among the chains jumping on the trend, though analysts say a congressional extension of clean-energy tax credits will be needed to maintain momentum. Wal-Mart, which has 17 stores and distribution centers testing solar panels, says a total build-out across the chain would create solar acreage roughly the size of Manhattan.